Expansible envelope



(No Model.) 2 Sheets-Sheet 1. 1). s. BROWN. EXPANSIBLE ENVELOPE.

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(No Model.) 2 SheetsSl1eet D. s. BROWN.

EXPANSIBLE ENVELOPE.

No. 531,832. Patented Jan. 1, 1895.

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DANIEL S. BROWN, OF PHILADELPHIA, PENNSYLVANIA.

EXPANSIBLE ENVELOPE.

SPECIFICATION forming part of Letters Patent No. 531,832, dated January 1, 1895.

Application filed October 29 1894- Serial No. 627,180. (No model.)

To aZZ whom it may concern.-

Be it known that I, DANIEL S. BROWN, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Expansible Envelopes for Containing Sheet-Music, Letters, Title-Deeds, &c., of which the following is a specification.

The object of this invention is such a structural formation of an envelope, or inclosure for containing sheets of music, letters, title deeds, or other articles of similar surface nature, or conformity; as will permit of lateral expansion of its end portions in an equal degree throughout their length, in accommodation to the bulk of matter desired to be inserted, and in which the end plaits confining the sides together are not in conjunction at theirlower ends with the adjacent portions of the side walls at that point, but separated and disconnected therefrom, so as to be independent thereof, thus permitting freedom of movement, whereby, when the envelope is filled with matter, the bottom shall extend laterally, thus forming a fiat, or level surface, and the sides of the envelope likewise become equally distended with said ends thus forming parallel surfaces of the sides equidistant from each other, throughout their length, which permits of the lower portions of the sides to bend over inward, thus converging toward each other, thereby bringing their lower surfaces into a level, or flat base, corresponding in breadth to that of the end plaits, or folds of the envelope when they are expanded.

The invention consists in an envelope formed from a single piece of material, so cut that all its parts shall be a unit when in the blank sheet, and having the portions forming the ends extended longitudinally, from the portions of which it is intended should serve as the side walls, and folding, or creasing said end pieces in their centers, also longitudinally, and uniting one free vertical edge of each piece to the opposite free end of one of the parallel walls of the envelope, thus per-' mitting the lower edge of the extension forming the end to remain unattached and not in connection with the lower edges of said walls forming the base, whereby when the envelope is filled with matter, said lower portions of the side walls bend inward and upward forming a level, or flat base, equal in width and length to the area of aperture within which the matter is inserted. This formation of an envelope, or inclosure, produces a receptacle in which the front and rear walls are continuously equidistant from each other at all points, either when closed, or extended, and when extended maintaining the bottom thereof. level throughout its plane in right angles to the Walls, whereby the contained matter is always retained in an extended, flat, or open state and condition, thus affording easy action of ingress, or egress, without the danger of mutilation, or being crumpled in appearance, or wrinkled in folds.

Another principle of the invention is to overcome the disadvantages resulting from the use of envelopes of rectangular box form, in which the corners are so frequently mutilated'and damaged by use, in consequence of their rigidity and in flexibility. As, with this invention, the side walls, (7,. a, the front and rear) by reason of their connected ends separated therefrom at their lower edges, and acting in the manner of hinged, or flexible joints at their points of contact with, and the central vertical crease in the ends permit of the expansibility of the envelope in a limited, or in a greater degree, in accordance with and with equivalent effect to suit the varying quantity of the, matter desired to be placed within the envelope, as hereinafter more fully described.

In the accompanying drawings, which make a part of this specification, Figure l, represents a blank A, as out to the desired dimensions in outline, previous to being creased and folded into an envelope. Fig. 2, repre sents a face view of the rear surface of the envelope to more clearly show the flap, or cover a. Fig. 3, represents a horizontal sec tion of the envelope, taken through the dotted line i, t, of Fig. 2, viewed in the direction of the arrow R. Fig. 4, represents an end view of the envelope, when devoid of contents.

Fig. 5, represents an end view of the envelope when expanded, and having the flap ex tended. Fig. 6, represents, a similar view with the flap closed over the top, or aperture of entrance to the envelope, and folded down upon the exterior surface of the rear wall.

Like letters of reference in all of the figures indicate the same parts.

In Fig. 1, a blank form is represented, from which the envelope is destined to be formed with its folds and creases, as represented by the series of dotted vertical lines 1/, 1 shown upon its surface, showing where the material of which the envelope is composed is folded at right angles to the ends a, and the outer fold of which, is to be united bya coating of adhesive gum to the contiguous part of the end of the rear Wall E, of the envelope, as seen in Figs. 2, and 3.

The lower edges of the ends 0, as at the line marked cl, in the various figures, are not united to the bottom of the envelope, but are open, and not connected therewith, and when the lower portions e, of the front and rear walls are bent at right angles to said walls the bottom of the envelope is formed thereby; said bottom being equal in area and extent with the receiving aperture of the envelope, thus permitting expansion, or distension of front and rear walls equidistant from each other throughout their inner surfaces, when the envelope is partially filled, or when it contains the complement.

Any pliable fabric, such as paper; cloth; parchment; or the prepared skin of an animal may be used for purposes of durability, or ornamentation, in the construction of the envelope.

In the drawings, the lower portions e, of the front and rear walls are represented as extending below the horizontal line of the base when closed, but, they can be so bent in the construction as to rest inside of the envelope when not in use, and be pushed downward'to 40 a level base by the weight of contained matter in the envelope, should this be found to be more desirable than the mode now contemplated.

In some cases it may be found advisable to crease and fold the bottom in a similar manner as that represented in the ends, and the method now shown for creasing and folding the ends be substituted therefor upon the sides. I

I claim as my invention and desire to secure by Letters Patent-- An envelope constructed of a single piece of suitable pliable substance, or fabric, in which the ends thereof are formed of integral portions of said substance, and bent at right angles to the front and rear walls, and having the outer, or free edge of each end only united to the contiguous surface of the wall, the lower edges of said ends being free and unconnected therewithfsaid ends being creased by vertical lines into equal folds or portions, to permit of resting within the inclosure, and the lower portions of said walls converging toward each other laterally forming an open ing at the base of the ends, in such a manner that when the ends are fully expanded laterally into a plane surface, the lower portions of the side walls which form the opening turn inward and upward horizontally meeting the lower edges of the ends, whereby level flat surfaces are formed in the ends and bottom, substantially in the manner and for the purpose herein shown and described.

DANIEL S. BROWN. lVitnesses:

THOMAS J. BEWLEY, S. E. W. BEWLEY. 

